<!DOCTYPE html>
<html>
  <head>
    <style>
      .my-input {
        border: 1px solid red;
        width: 300px;
      }
    </style>
  </head>
  <body>

    <!-- 文本输入框 -->
    <input type="text" class="my-input" />
    <!-- 按钮：点击按钮开始挂载 -->
    <button id="start-render-button">开始挂载</button>

    <script src="index.js" ></script>
  </body>
</html>